Tried this recently on a new thin laptop that comes with UEFI and Windows 8. I made a bootable Slackware ISO image, processed it so it is USB bootable then wrote it to a USB stick as per instructions found in http://taper.alienbase.nl/mirrors/sl...nux/README.TXT, then tried booting in UEFI mode off the USB, Grub menu came up and I booted the non-kms option, unfortunately I got an unreadable console (and the penguins are badly mangled too)
Anyone had a similar issue?

business_kid

10-05-2013 02:11 PM

One of your images (all the bits of words all over the place) is a classic problem of horizontal frequency. Every box is/was supposed to come up at 640x480x60hz initially and then you can set fancy settings if you want. I guess the fancy stuff is going wrong.

jtsn

10-05-2013 07:42 PM

Isn't 1024x768 the regular resolution of UEFI framebuffer? That is what Windows 8 requires for its splash screen.

Some more hardware info is required for solving this issue.

business_kid

10-06-2013 12:20 PM

m$ could have upped it to 1024x768 - I don't track m$. It's still no use to The OP That's a 4:3 resolution, and the screenshots are of a 16:9 monitor.

The screenshots make clear that the video is running at the wrong setting. Is there a vga= line in the boot sequence?

jtsn

10-06-2013 12:24 PM

Quote:

Originally Posted by business_kid
(Post 5041013)

m$ could have upped it to 1024x768 - I don't track m$

They do that since 2006 I think. Maybe we don't track MS, but PC hardware/firmware vendors surely do.

Quote:

Is there a vga= line in the boot sequence?

vga= doesn't apply, because it controls the VESA/VGA console driver, which is disabled on EFI systems.

volkerdi

10-06-2013 01:11 PM

What does the KMS boot option do?

dr.s

10-06-2013 05:54 PM

Quote:

Originally Posted by jtsn
(Post 5040721)

Some more hardware info is required for solving this issue.

Thanks for the feedback. It's an Acer Aspire V5-472 with Intel HD 4000 graphics and an i5 processor. It came with Windows 8 and UEFI.

together with the KMS option. Try ELILO. Or try doing a legacy boot, so you get a VGA text mode console.

business_kid

10-07-2013 02:01 AM

The HD4000 is not a difficult card to drive. I have one here - no issues with or without uefi. I have slackware & fedora installed. The hd I removed had uefi & windows 8. Could it be the monitor?

dr.s

10-07-2013 06:54 AM

Quote:

Originally Posted by jtsn
(Post 5041149)

Try

Code:

video=efifb:off

together with the KMS option.

This option seems to turn off the console completely, with or without KMS, as soon as Grub loads the OS.

dr.s

10-18-2013 01:10 AM

I installed Slackware by booting in legacy mode, this went smoothly as usual. At that point I set up elilo, grub2 and rEFInd in the EFI partition, rebooted and switched back to UEFI mode.
Grub2 and elilo booted into the scrambled console. However, booting via rEFInd either directly or by chainloading elilo (or grub2) worked, not really sure why. May be rEFInd somehow sets up the correct resolution and/or framebuffer?

dr.s

03-30-2014 10:01 AM

It turns out rEFInd is using graphics mode by default, Grub2 and elilo are not during EFI boot. The Slackware EFI boot off the USB image runs in console mode.
When chainloading Grub2 or elilo off rEFInd they somehow kept the correct mode, otherwise they'd boot into a scrambled screen. I managed to EFI boot directly off Grub2 (without rEFInd) by setting the gfxmode, setting the gfxpayload to "keep" and switching to a gfx terminal. Also a font has to be loaded off the file system (not available on the Slack USB) otherwise you'll get an unreadable menu once you switch to the gfx terminal but booting would still work once you press enter on an item.